Secondary Ocular Hypertension with Exophthalmos as the First Presentation of Endogenous Cushing's Syndrome

Cushing's syndrome results from excessive exposure to exogenous or endogenous steroid, while cushing's disease is hypercortisolism from an adrenocorticotropic hormone-secreting pituitary adenoma. Secondary ocular hypertension (OHT) accompanied by exophthalmos as the initial presentation of endogenous Cushing's syndrome has rarely been reported.

A 46-year-old Thai woman was referred for OHT treatment despite maximum tolerance to medication. Intraocular pressure (IOP) was 21 mm Hg (right eye) and 25 mm Hg (left eye). Visual acuity was 20/20 in both eyes. Bilateral eyelids were swollen without any palpable masses. Exophthalmometer measurements were 24 mm (right eye) and 23 mm (left eye). Extraocular muscle movements, anterior segment, gonioscopy, and dilated fundoscopic exams were normal bilaterally. Optic nerve head was unremarkable in both eyes. Optical coherence tomography showed marginal inferior thinning of the retinal nerve fiber layer and ganglion cell layer in left eye. Computerized visual field 24-2 was normal bilaterally. She was diagnosed with secondary OHT with exophthalmos in both eyes. Thyroid function and thyroid antibody tests were unremarkable. Orbital and brain computed tomography revealed exophthalmos with an increase of retrobulbar fat bilaterally and a hypodense pituitary lesion. She was diagnosed with Cushing's disease and underwent endoscopic transsphenoidal adenectomy. At 6-month postoperatively, IOP decreased to 16 mm Hg (right eye) and 17 mm Hg (left eye), without any IOP-lowering medications. Exophthalmos also improved as exophthalmometer measurements were 20 mm (right eye) and 19 mm (left eye).

Endogenous Cushing's syndrome should be included in the differential diagnosis of secondary OHT with exophthalmos.